<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <ul>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
    </ul>
    <script>
        let arr = [10,20,30,100,200];
        for(let val of arr){
            console.log(val);
        }

        let oLis = document.getElementsByTagName("li");
        for(let val of oLis){
            console.log(val);
        }
    </script>
</body>
</html>